Clearance-testing instrument



N. T HABRINGTON. v CLEARANCE TESTING INSTRUMENT.

APPLICATION man FEB. 1. 1919.

1,437,053. Patented Nov. 28, 1922.

Petentea Nev. 2s, 1922.

v(narran `STATI-:s

NORMAN T. HARRINGTON., F CLEVELAND, OiHIO.

CLEAANCE-TESTING INSTRUMENT.

. application med February 7, 1919. serial No. 275,491. 'l

' To all 'wlwm it may cmwern Be it known that I, NORMAN HARRING- TON, a citizen of the United States, residing at Cleveland, inthe county of Cuyahoga and 5 State of Ohio, have invented a certain new and usefullmprovement in Clearance-Testing Instruments, of which the following is a full, clear, and exact description, reference being had tothe accompanying drawings.

This invention relatesI to gauges and has for its general object to rovide an instrument of this character whlch will enable the amount of clearance between a given body e and aecooperating body to be. conveniently ascertained and indicated. While my invention possesses special utility in determining the clearance between cooperating threaded bodies or objects, it is not limited in its application to such bodies or objects.

.20 Further and more limited objects of the invention will appear hereinafter and will be realized in and through the combinations of elements embodied in the claims forming part hereof. t

Referring to the use of my instrument in connection with threaded objects, itshould be stated that, so far as I am advised, the F i general practice of determining the accu` racy of such objects is to apply the same to a cooperating threaded standard gauge block and determine, by the closeness or looseness of the iit between the threads of the object and the gauge block (through the sense of feeling) the accuracy of the threading and the amount of clearance between the. threads of the said object and those`of the gauge block. If the threads of the object tested bind too tightly upon the threads of the gauge block, or if too much clearance between such threadsis apparent, the object is discarded. Where myinstrument and invention are employed in connection with a threaded object, it `is possible to determine,

1 by reference to a pressure indicator, whether the clearance between the threads of such object and'those of the gauge block is within the limits of tolerance permitted or whether such tolerance limits have ,been exceeded, thus enabling the gauging of such objects to be efected withspeed and accuracy. v In the drawings forming part hereof, I have shown my auge as adapted for use with both interna 1y and externally threaded ob'ects.

n said drawings, Fig. l1 represents a central `longitudinal sectional view through the lnstrument where used in connection with an externally threaded object, the pressurev mdicatingdevice and an externally threaded object being shown in elevation; Fig. 2 a sectional yiew corresponding to the line 2.-2 of Fig. 1, the pressure indicating device here also being shown in elevation; Fig. if an end .elevation ofthe gauge, the pressure lndlcating device being omitted; Fig.f4 an end elevation of the standard orA mast-er gauge block employedwith the instrument showninthe preceding views, the view correspondlng to the line 4 4 of Fig. 1 and looking in the direction of the arrows; and Fig. 5 a central longitudinal `sectional view through the standard or master p lug employed with my gauge when the -object to be tested is internally threaded, such object alsobeing shown in section.

Describing by reference characters the various parts illustrated herein, and-with particular reference to Figs. 1 to 4 inclusive, wherein the auge is employed for the testlng of externa ly threaded objects, 1 denotes a handle having a bore 2 therethrou h. or convenience of description, the portlon of the gauge which receives the object to be tested will be referred to as the front and the opposite portion as the rear; furthermore the instrument will b e assumed to be operated in the positions shown in Figs. 1 andv 2,v and thewords top and bottom and upper and lower will be employed accordingly. The rear end .of the boreV 2 .is enlarged and tapered and provided with Y a thread, indicated at 3, said thread cooperating with an external thread 4 on-a connection 5 having a bore 6 therethrough. A tube 7 is detachably secured to the connection 5, as by means of a shoulder 8 on the end of said tube and a shouldered or ianged-nut 9 threaded onto the rear end of said connection.` 1

Projectin forwardly from the handle 1 is a neck" 10 aving a bore -11 therethrough, said bore constituting a reduced extension of the bore 2. Mounted in the neck is a rotary valve 12 having a port 13-extending therethrough and adapted to register with thefront andrear portions of the bore 11, the valve being' provided with an operating handle 14.v The valve is shown as tapered .merging with a head 16, said head having a central tapered opening 17 therethrough. The lower end of the opening is-shown as enlarged, as indicated at 17a, thereby to provide an annular shoulder 18. The bore 17 10 17a receives therewithin a pressure reducing valve comprising a tapered casing 19 closed at its enlarged upper end to provide a cap 19a and having itsopposite end reduced and provided with an external thread 20. The casing 19 is provided with a cylindrical bore 2l extending from the reduced end thereof, the said bore being enlarged at the opposite or upper end of the casing, as indicated at 22, to provide a chamber at and within such end and beneath the cap 19a. Y

Mounted in the bore 21, 22, is a reciprocable valve body, lindicated generally at 23,

said body being preferably cylindrical in shape throughout the major portion of its length to conform to and form a working lit with the bore 21.l- The upper end of the valve body within the chamber 22 and within the upper portion ofthe bore 21 adjacent thereto, is reduced in diameter, as indicated at .24, providing an annular ledge at 25. At a short distance above the center, the valve body is provided with a transverse port 26 extending through and across the central portion of said body. From the central p01'- tion of this port, the port 27 extends axially of the valve body through the upper end thereof. A pair of diametrically opposed ports 28 extend from the port 27 to the chamber surrounding the extension 24 and place the port 27 in communication with said chamber.-

The casing 19 is provided with a wide I. annular channel 29 in its outersurface, the

upper portion of said channel communicating with the chamber 22 by means -of diametricallyopposed ports 30.. With the valve body in the position shown in Fig. 2, the port 26 communicates by means of diametricallyopposed ports 31 in the casing 19 with the upper portion of a wider annular portion 32 in the outer surface thereof. The valve body `is normally held with its upper end seated against the upper cap of the casing 19 by 'means of a coiled spring 33 bearing at one end against the bottom of the valve body and at its other end against a cap 34 which is threaded upon the lower end of said casing` there being a gasket of packing material 34a interposed betweenl the topof the side wall of the cap and the shoulder 18.

At one side of the opening 17, the head 16 is provided with an internally threaded bore 36 extending from the rear end thereof. In

front of the threaded portion thereof the' bore is reduced, as shown at 36, and is still further reduced at its extreme front or discharge portion, as indicated at 36". Mounted in the threaded portion 36' of the bore is a plug 37 Having a sleeve 37a at the front end thereof. The plug is shown as threaded throughout its entire external surface, with the exception of an annular recess 38, which communicates, by means of a port'39, with the annular recess 29. The plug is also provided with a transverse port 40 communicating with opposite ends of the recess 38 and with a short central port 41 communicating at its rear end with said through- Aport. 'i

Mounted within the sleeve 37 and in the reduced portions 36afand 36b of the bore 36 is a flow reducing nipple or bead 42 having a central chamber 43 at the rear end thereof, communicating with the port 41, and a central calibrated restricted port 44 extending forwardly from said chamber and commuj nicating at its front end with a cham'ber 45 provided within the head and at the rear of the gauge block 46.

Projecting from one side of the liead is a pressure indicating gauge 46 having an indicator` 47 and connected by the nipple 48 with the chamber 45 by means of a port 49.

1A gauge block, shown in Figs. 1, 3 and 4, is employed for the testing of externally threaded objects. It comprisesl a body having a central internally threaded bore 50, the rear portion of said body being cylindrical to provide a close fit within a cylindrical seat provided therefor in the front of the head. The front of the gauge block is shown as reduced in diameter as compared with the rear portion and is angular in outlinesee 51-to receive a. flanged internally threaded skirt 52 whereby the block may be secured-within the front of the head, suitable packing 53 being interposed'between the flange andthe block and` if desired, between the flange and the frontsleeved por,- tion of the head, `thereby to prevent leakage of pressure fluid from the ports in the gauge block.

54 denotes ports extending forwardly from the rear of the gauge block,on opposite sides of the central prtion thereof, the front ends of saidports communicating each in turn with a port 55 extending inwardly to the threaded bore of the block. The block may be provided with an annular recess in the rear face thereof, adapted to receive an annular rib 56 carried by the head, thereby to prevent leakage from the chamber 45. Packing The bore 50 is provided with grooves 57 extending longitudinally from the front to the rear thereof'. Four such grooves are shown each being' angularly spaced' from the ports 55;.Y The grooves provide venting ports, and these, venting ports are shown as spaced about 90 degrees apart; the centers of `the receiving ends of the ventingv ports are preferably spaced about twice the width of the ports 55 from the centers of the delivery ends of the latter. If desired, the head 36 may be provided with suitable supporting studs or feet 58.

With the parts arranged and constructed as described the instrument will be operated in the following manner: An externally threaded object to be tested, such as A, will be screwed into the bore 50. `Air or other pressure fluid will be admitted through the pipe 7, handle l'and valve 12 tothe annular recess 32, whence` it will pass, by ports 31,

. 26, 27, and'28 into the chamber 22 and thence by the ports 30, annular recessy 29, port 39, and annular recess 38 and port 40 and chambers 41, and 43, to the restricted bore or port 44 of the nipple or bead 42. By means of the vent port 59 communicating with the recess 38, any moisture or other foreign matter in the pressure fluid will be blown out,

the venting port being of such small crosssectional area asto exert no appreciable effect upon the pressure of the fluid in the chambers -41 and 43. The fluid, thus reduced in pressure by the valve 23,V enters the chamber 45 and passes through the ports 54 and 55' to the space between. the threaded object A being tested and the threaded portion of the gauge block corresponding to the width of the last mentioned ports. The amount of leakage between the object tested and the gauge block will indicate, .through the pressure gauge 48, the clearance between such threads. Pressure within the chamber 22 will move the body 23 downwardly,

` thereby cutting down or cutting oif the supthe instrument 'and the objecttested. With;

ply of pressure fluid through the recess 32 and ports 31, 26, and 27 andl delivering the fluid at a predetermined pressure to the chambers 41 and 43 and to theibead 42. The bead serves to' restrict the rate of f iow of the pressure fluid from the chambers 41 and 43 to the chamber 45-a11'd to the space between fthe clearance or leakage area between the gauge block andthe article testedequal to the area of the port `44, the pressure of the [luid supplied to said block' bythe bead 42 will be about half that which exists inthe chambers 41 and 43. This reduction of pressure makes it possible tocalibrate the gauge 46v to indicate clearly small variations in pressure-due tothe testing 'of successive between the diameters of the objects? tested and that ofthe bore of the gauge block.

The provision of the ports 26 and 28 and i the annular recesses 29 and 32 'enables me to balance the pressure on opposite sides of the For instance, withf a maximum site sides of the article tested and thus ensures the centering of such object with respect to the gauge block.

The venting port 34=1\in the cap 34 permits moisture and leakage past the valve 23 to' escape and also serves to steady the action of the valve, preventing fluttering thereof.

.In practice, two externally threaded plugs may be employedl in connection with objects of the same kind, One of these standard gauge plugs will be so threaded as to provide a substantially-perfect fit with the bore of the gauge block, giving a minimum of clearance; the other will be threaded so as to fit more loosely within the bore of the block and provide therewiththe maxlmum clearance permissible. Each of these plugs will be applied to thegauge block, the pressure fluid turned on, and the gauge 46 read. Any object to be tested showing a pressure indication within these two limits indicated by the gauge 46 will be acceptable.

An important advantage of my invention resides in the fact that the auge block need not be renewed frequently y reason of the wearing of the threads. the threads will affect the readings in connection with the standard plugs equally with the readings of the tested objects. It is necessary, therefore, only to takethe readingV of the standard plugs from time to time and or plugs come within the limits obtained by such readings.

This wearing of` '.see that the readings of the tested objects Q In Fig. 5 I have shown the form of gauge to the groove 56 and a port 62 extending from the rear face and adapted to communicate with the chamber 45 through `a radial port 63 extending tothe rear of a central internally threaded bore 64 which receives the externally threaded rear'end of a gauge blockplug 65. This plug is providedfwithl an axial port-66 communicating with the port 63 at its rear end and at its'front end with the transverse through-port 67. The front of the plug 65 is externally threaded izo' to receive an internallythreaded object B tobe tested and'is provided in its'external surface with venting recesses or grooves 68 extending longitudinally thereof` fromv the port 67. `-These ports serve the` same .pur-

pose as the ports 57 ;fthat is to'say, lthe presfsure fluid admitted tothe space between the threads of the externally and internally threaded objectsv will flow. between the threads thereof as far as said ports and will then -be vented thereby to the atmosphere.

As a basis for comparison, two standard internally threaded members will be em- 1 ployed, one of said members providing with the plug 65 themaximum permissible-clearance and the'oth'er the theoretical minimum clearance characterizing a perfect thread 1n the tested object. By-making the bead or nipple 42 removab'le, I am enabled to adapt the instrument to the particular grade of inspection-accuracy required, this result being accomplished by using a bead or nipple having a small bore where great accuracy is required and one having a larger bore where a less degree of accuracy is required.

The instrument shown herein is a selfcontained device embodying means for regulating the pressure of a fluid, means for reducing the rate of flow of the fluid the pressure whereof has been so regulated, and for delivering the Afluid the rate of How whereof has been so. reduced to a space or joint between the instrument and the object to be tested, with means for indicating the pressure, or leakage, of such' fluid at suchdjoint or at or through the space being teste While I have shown my invention in de- ,L'A gauge having a portion adapted to'receive an object to be 'tested,'

said portion being provided with exhaust ports, means for conducting fluid under, pressure to said portion, anda', device forv indicating the leakage of such fluid between the object tested and said exhaust ports.

2- In an instrument of the character described, Vthe combination of a gauge block having a surface provided with exhaust ports and adapted tocooperate withv the complementary surface of an object to be tested, meansJ for conducting fluid under pressure to the space between said surfaces, and a device forindicating the leakage of such fluid between such space'andexhaust .3. An instrument of the character described having afportion for application to anobject to be tested, apart provided witha conduit for Huid under pressure leading to said portion, a-devlce for'regulating'the n A i pressure of the luid conducted through said conduit, a device for reducing the rate of flow of the fiuid delivered from the first mentioned device to said portion, and means' for indicating the pressure of the fluid in said rtion.

4. n an instrument of the character described having a portion for application to an object to be tested, a part provided with a conduit for fluid under pressure leading to said portion, a device for re ating the pressure of the fluid conducted ough said conduit, means for reducing the rate of flow of the fluid delivered from the pressure reducing device to said portion, and means for indicating the pressure of the fluid in said portion.

5. An instrument of the character described having a portion adapted for application to an object to be tested, a part provided with a conduit for fluid .under pressure leading to said ortion, a pressure regulating device in conduit, a chamber 1n said conduit and to which the Huid delivered from said deviceis conducted, a bead in said conduit having a restricted port and receiving the fluid delivered from said chamber, and -means for indicating the pressure of the fluid in, said portion. Y

6. An instrument of the character described having a portion-adapted to cooperate with a surface of an object to be tested and a part provided with a conduit for fluid under pnessure extending to such' portion, an automatic pressure regulating valve yin saidaconduit, a chamber in said conduit to. which the fiuid delivered 'from said valve is conducted, said chamber having a venting port, a bead in said conduit having a restricted port through which the fluid from said, chamber is conducted, the aforesaid portion of said instrument being located beyond said bead, and a device for indicating the, rate of leakage of the pressure fiuid 1h10 through or across the surface-of the object to be tested.

7. An instrument of the character described having a portion adapted to cooperate with ,an object lto be tested and a part provided with a conduit for Huid under' pressure extending to' such portion, an automatic pressure regulating device in` said conduit, a chamber in said conduit; to which the fluid delivered from said device is conducted, said conduit having a restricted bore through which the fluid from said chamber is conducted the aforesaid portion of said instrument being located beyond vsaid bone, and a device for indicating the rate of leakage of the pressure fluid through or across the surface to be tested.

'8.' In an instrument of the character de-` scribed, the combination 'of a gauge block having a surface adapted to cooperate with the complementary surface, of an object to 13o tested, and tg provide a space therebetween, means for'- elivering fluid under pres# sure to a plurality 'of polnts between such surfaces, and a pressure indicating device operatively connected with said means.

v9. In aninstrument of the character described, the combination of a gauge block having a portion adapted to cooperate with an `object to be tested, a pressure fluid conduit in said instrument for conducting Huid -under pressure to said portion, means asso-- ciated with said instrument for regulating the pressure of such fluid, means for reducing therate of flow of the fluid delivered from the regulating means andl for sup lying the'same totheo said portion, and a uid "pressure gauge operatively interposed between such pressure reducing means and' said portion. I

10. In an instrument of the character d scribed, the combination of a gauge block havin a portion adapted to cooperate with an obJect to be tested, means 'forl supplying fluid under pressure to said portion, means for regulating the pressure of such fiuid, means for restricting the flow of the fluid from such regulating means to said portion,

and means for indicating the pressure of the fluid-in said portion'. 1

11. In an instrument of the character described, the vcombination of a gauge block having a surface adapted to cooperate with .the com lementary surfaceV of an object to be teste said blockl having ports ada ted to commumcate with angularl space tions of the space between said surfaces and one or more venting ports adapted to communicate with .the space between said surfaces, means for delivering fluidunder pressure through the first mentioned ports, and a fluid -preure indicating device operatively connected with the space between said surfaces to which the pressure' fluid is delivered. v

12. In an instrument of the character described, the combination ofv a head, a auge block detachably kconnected to said hea and having a surface adapted to cooperate with the f complementary surface of an object to be tested, said block having ports adapted to communicate with angularly spacedygpori scribed, the combination of. a gauge ,block having .a surface adapted to cooperate with the complementary surfacev of an object-to be tested said block having orts communieating with angularly space portionsof the space between said surfaces, means lfor supplying fluid .under pressure to said 'ports and ai pressure indicating device operatively connected with the space between said surfaces, said blocks having a plurality of venting ports communicating with said space, said venting ports being spaced apart in a' plane eXtendlng transversely of said block.

14. A gauge block having a threaded surface adapted to cooperate with the threaded surface of an object tol be tested, said gauge block having one or more ports for delivering fluid under pressure to one or more por- 'tions of' its threaded, surface. and one or more venting ports in the threaded surface of such block, the venting port or ports extending longitudinall of such surface and across the threads t ereof and angularly spaced from the first mentioned port or ports, and nieans for supplying fluid under pressure to said port or ports.

15. A gauge b ock having a threaded surface adapted to cooperate with the threaded surface of an object to be tested, said gauge block having one or more ports for delivering Huid under pressure to one or more portions of its threaded surface and one or more venting ports inthe threaded surface of such block and extending longitudinally thereof and across the portion of such surface'to which the pressure fluid is delivered, and means for supplying fiuid under pressure to said port orvports. f

16. A gauge block having a'threaded surface provided with exhaust ports and adapted to cooperate with the complementar threaded surface of an object to be teste 'means associated with said block for deliverin its t readed surface, and means for indicating the leakage of said iuid between sa1d threads andfexh'aust ports.

fiuid under pressure'to a portion of"` 17. A gauge block having a threaded surface adapted to cooperate with the complementary threaded surface of an object to be tested and provided with a plurality of angularly disposed ports` for conducting fiuid under pressure to corresponding angularly spaced ortions of its threaded surface, and means fdr supplying fluid under pressure to said ports. Y

" 18." A gauge block having a threaded surface adapted to cooperate with the complementary threaded surface of. an object to be tested and provided with a,portfor conducting fluid. under pressure to 'a portion of its threaded' surface and with la venting port extendin transversely, of the threads of -such sur ace and angularly spaced from thes first mentioned port, and means for supplying fluid under pressure -to'the first mentioned port.

l19. A gauge block having a threaded sur- -face adapted to cooperate with the compleits threaded surface and. with a venting port extending longitudinally of such threaded surface and transversely of the thread thereof, and angularly spaced from| said rst mentioned ports, and -means 'for supplying fluid underpressure to the first mentioned ports. i 20. A gauge block having a surface adapted to cooperate with the complementary surface of an object to be tested and provided with a plurality of angularly disposed ports for conducting Huid under pressure to corresponding angularly spaced portions of the first mentioned surface, and means for supplying Afluid under pressure to said ports.

21. A gauge block having a surface adapted to cooperate with the complementary surface of an object to be tested and provided with a port for conducting uid under pressure, to a' portion of the first mentioned surface and with a venting port in such surface and angularly spaced from the first mentioned port, and means for supplying fluid under ressure to the first mentioned port.

\ 22. gauge block having a surface adapted to cooperate-with .the complementary surface of an object." to be tested and provided with a plurality of angularly disposed ports communicatin withcorresponding angularly spaced'portmns of the first mentioned sur- 'face andE with` a venting port extending longitudinally of the rst mentioned surface and angularly spaced from said first mentioned ports, and means forsupplying fluid underpressure to the first mentioned ports.

23. In an instrument ofthe character described, the combination of a gauge block `having a surface adapted tof cooperate with the complementary surface of an object to be Qtested and provided with one or more ports in said block adaptedto communicate with a corresponding portion or portions of the space between said surfaces, said block having Aaconduit for conducting fluid pressure to said port or ports, said lconduit having therein a removable pressire reducing bead or nipple having la restricted bore therethrough, and a pressure indicating device operatively ports. Y c

24. In an instrument, of the character deconnected withd thev said port or scribed, the combination of a head, a gauge block' detachably connected to said head and having a surface adapted to cooperate with the complementary surface of an object to be tested, said head haying one `or more ports adapted to communicate with a corresponding portion or portions of the space between 'said surfaces, means for supplying pressure fluid to said head,` said instrument having a conduit for conducting such fluid from said head to said port or ports, said conduit having therein a removable pressure reducing bead or nipple having a restricted bore ltherethrough, a blow-out port communicating with said conduit on the inlet side of said bore, and a pressure indicating device operatively connected with the first mentioned port or ports. A i

which pressure fluid is delivered, said inm strument having a conduit extending from said device to the port or ports in said block, a pressure reducing bead or nipple in said conduit and having .a restricted port therethrough, a chamber in said conduit at the inlet end of said bead or nipple, afblow-out portcommunicating with said chamber, and a pressure indicating device'operatively connected with the first mentioned port or ports.

26. In an instrument of the character described, the combination of a head, a gauge block detachably connected7V to said head and having a surface adapted to cooperate with the complementary surfacea of an object to be tested, said head having one or more ports adapted to communicate swith a corresponding portion or portions of the space between said surfaces, means for sup' ply-ing fluid under pressure to said head, an automatic pressure re ulating devicein said headl to which the uid is delivered, said head having -a conduit communicating with the pressure regulating device and with said port or ports, said conduit having an internally threaded chamber' "therein, va plug threaded` into said chamber and having la chamber to'which the fluid isconducted from I' the regulating device, a nipple or bead supported in said conduit'byrsaid block and having a port therethrough communicating at itsinletend with said through port, and a-lgaug'e. operatively connected with the first mentioned port or ports.

'27, In an instrument of the character described, the combination of a. head, a gauge block detachably connected to said head and having a surface adapted to coautomatic pressure regulating'device in said 130 head to which the Huid is delivered, said demeans for reducing the rate of How of the vice comprising a reciprocable valve body in uid in said conduit, and a gauge operatively said head, a cap havinga venting port, a connected with the first mentionedport or 10 spring interposed between said cap and said' ports.

5 valve body, said instrument having a -co'n- In testimony whereof I hereunto aix my duit'communicating with the pressure regsignature.

ulating device and with said port or ports, NORMAN T. HARRINGTON. 

